feat: fpw plugins, validation/crawl perf, WS stats, test DB isolation

- Add Free_Proxy_Website-style fpw_* plugins and register them
- Per-plugin crawl timeout (crawl_timeout_seconds=120); remove global crawl_timeout setting
- Validator: fix connect vs total timeout on save; SOCKS session LRU cache; drop redundant semaphore
- Validation handler uses single DB connection; batch upsert after crawl; WorkerPool put_nowait
- Remove unused max_retries from settings API/UI; settings maintenance SQL + init_db cleanup of deprecated keys
- WebSocket dashboard stats; ProxyList pool_filter and API alignment
- POST /api/proxies/delete-one for IPv6-safe deletes; task poll stops on 404
- pytest uses PROXYPOOL_DB_PATH=db/proxies.test.sqlite so tests do not wipe production DB
- .gitignore: explicit proxies.test.sqlite patterns; fix plugin_service ValidationException import

Made-with: Cursor

app/plugins/fpw_gatherproxy.py

@@ -0,0 +1,61 @@
+"""gatherproxy.com 页面内嵌 JSON（PROXY_IP / PROXY_PORT）。"""
+import re
+from typing import List
+
+from app.core.plugin_system import ProxyRaw
+from app.plugins.base import BaseHTTPPlugin
+from app.core.log import logger
+
+
+class FpwGatherproxyPlugin(BaseHTTPPlugin):
+    name = "fpw_gatherproxy"
+    display_name = "GatherProxy"
+    description = "gatherproxy.com 内嵌代理 JSON（站点常有限流）"
+
+    def __init__(self):
+        super().__init__()
+        self.urls = [
+            "http://www.gatherproxy.com/proxylist/anonymity/?t=Elite",
+            "http://www.gatherproxy.com/proxylist/country/?c=United%20States",
+        ]
+
+    def _extract_from_text(self, text: str) -> List[ProxyRaw]:
+        results: List[ProxyRaw] = []
+        for m in re.finditer(
+            r"PROXY_IP['\"]?\s*:\s*['\"]([\d.]+)['\"].{0,120}?PROXY_PORT['\"]?\s*:\s*['\"](\d+)['\"]",
+            text,
+            re.DOTALL | re.IGNORECASE,
+        ):
+            ip, port = m.group(1), m.group(2)
+            if port.isdigit() and 1 <= int(port) <= 65535:
+                try:
+                    results.append(ProxyRaw(ip, int(port), "http"))
+                except ValueError:
+                    continue
+        for m in re.finditer(
+            r"\{[^{}]*\"PROXY_IP\"\s*:\s*\"([\d.]+)\"[^{}]*\"PROXY_PORT\"\s*:\s*\"(\d+)\"[^{}]*\}",
+            text,
+        ):
+            ip, port = m.group(1), m.group(2)
+            if port.isdigit() and 1 <= int(port) <= 65535:
+                try:
+                    results.append(ProxyRaw(ip, int(port), "http"))
+                except ValueError:
+                    continue
+        return results
+
+    async def crawl(self) -> List[ProxyRaw]:
+        seen = set()
+        out: List[ProxyRaw] = []
+        htmls = await self.fetch_all(self.urls, timeout=10, retries=1)
+        for url, html in zip(self.urls, htmls):
+            if not html:
+                continue
+            for p in self._extract_from_text(html):
+                k = (p.ip, p.port)
+                if k not in seen:
+                    seen.add(k)
+                    out.append(p)
+            if out:
+                logger.info(f"{self.display_name} 自 {url} 累计 {len(out)} 条")
+        return out